The accused, identified as Ajay Kumar, was released from jail in 2012 upon his acquittal by Delhi High Court in a murder case.
"Since then, Kumar had been into extortion and was involved in many cases of gang wars for gaining supremacy in the south part of Delhi," said Joint Commissioner of Police (Crime), Ravindra Kumar Yadav.
He was arrested today from Nehru Place by a crime branch team following a tip-off. On April 5, Kumar and six of his associates had abducted and murdered two members of a rival gang in south east Delhi's Sangam Vihar area, police said.
Kumar was arrested for two murders and lodged in jail for a few years before being acquitted by high court.
Earlier, before taking to crime, he had been assisting his father in his refrigeration and welding business. A father of two girls, Kumar separated from his family after he entered the world of crime, police added.